Online tolerance lookup tool - web-based tolerance query program. Data strictly conforms to the national standard GB/T 1800. Simply enter the relevant parameters to quickly obtain limit deviations and other information.
Introduction
You can view the features and usage instructions of this tool in the Tool Introduction.
Tolerance Query
Tolerance Query
| Grade | Tolerance Code | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IT6 | |||||||||||||||||||
| IT7 | |||||||||||||||||||
| IT8 | |||||||||||||||||||
| IT9 | |||||||||||||||||||
| IT10 | |||||||||||||||||||
| IT11 | |||||||||||||||||||
Changelog
2026.3.31
1. Added hole and shaft preferred tolerance zone keyboards. According to GB/T 1800.1—2020, tolerance zone codes should be selected from the corresponding hole and shaft tolerance zone codes provided whenever possible.
2. Clicking a keyboard button automatically imports the corresponding tolerance code and grade.
2023.12.16
1. Fixed incorrect fundamental deviation data for holes with tolerance grade G and basic size greater than 180 up to 250.
2022.7.26
1. Fixed program bugs.
2. Thanks to user Kallece for pointing out query data errors.
Hole Tolerance Query Notes
1. For basic sizes less than 1mm, A and B of all grades are not used.
2. CD, EF, FG of all grades are mainly used in precision machinery and watchmaking.
3. IT14 to IT18 are only used for basic sizes greater than 1mm.
4. Tolerance zones J8, J10, etc. are symmetrical about the zero line; their deviation values can be found in JS9, JS10, etc.
5. For basic sizes greater than 3mm, deviation values of K above IT8 are not specified.
6. The deviation values of J7 for basic sizes greater than 3~6mm are equal to those of JS7 for the corresponding size range.
7. Tolerance zones N9, N10 and N11 are only used for basic sizes greater than 1mm.
8. For basic sizes up to 24mm, deviation values of T5 to T8 are recommended to be replaced by U5 to U8. If T5 to T8 is required, calculate according to GB/T 1800.3.
9. For basic sizes up to 14mm, deviation values of V5 to V8 are recommended to be replaced by X5 to X8. If V5 to V8 is required, calculate according to GB/T 1800.3.
10. For basic sizes up to 18mm, deviation values of Y6 to Y10 are recommended to be replaced by Z6 to Z10. If Y6 to Y10 is required, calculate according to GB/T 1800.3.
11. Deviation values of IT1 to IT5 for basic sizes between 1500mm and 3150mm are tentative values.
Shaft Tolerance Query Notes
1. For basic sizes less than 1mm, a and b of all grades are not used.
2. cd, ef, fg of all grades are mainly used in precision machinery and watchmaking.
3. IT14 to IT18 are only used for basic sizes greater than 1mm.
4. For basic sizes up to 24mm, deviation values of t5 to t8 are recommended to be replaced by u5 to u8. If t5 to t8 is required, calculate according to GB/T 1800.3.
5. For basic sizes up to 14mm, deviation values of v5 to v8 are recommended to be replaced by x5 to x8. If v5 to v8 is required, calculate according to GB/T 1800.3.
6. For basic sizes up to 18mm, deviation values of y6 to y10 are recommended to be replaced by z6 to z10. If y6 to y10 is required, calculate according to GB/T 1800.3.
7. Deviation values of IT1 to IT5 for basic sizes between 500mm and 3150mm are tentative values.
